Okay, so now I have a Lion VM with 2 GB of RAM set up with Xcode 4.2.1, and I've just started to take a look at MentalPower's work. He hasn't been around for a couple of weeks, but maybe he's had more progress/insight since his last post on this from five months ago.
In any case, are there any recommended reading sources on either the structure of the FSO codebase or on how to create/update an Xcode project file? I'll go looking for stuff on my own, too. I don't yet know whether I'll end up using his work or writing a new project file, although I'll look at his work and at the current FSO Xcode project file for inspiration.